Abstract

Purpose: Pemetrexed is established as first-line treatment with cisplatin for malignant pleural mesothelioma and advanced nonsquamous non–small-cell lung cancer (NSCLC) and as single-agent second-line treatment for nonsquamous NSCLC. Because the structure and pharmacokinetics of pemetrexed are similar to those of methotrexate, and methotrexate is associated with severe toxicity in patients with third-space fluid (TSF), the safety of pemetrexed in patients with TSF was evaluated.

Experimental Design: Patients with TSF (pleural effusions, ascites) and relapsed, stage III/IV NSCLC or malignant pleural/peritoneal mesothelioma were treated with pemetrexed (500 mg/m2) on day 1 of each 21-day cycle. TSF was drained at any time only if clinically indicated. Plasma samples were collected during cycles 1 and 2 to compare pemetrexed concentrations with reference data from patients without TSF.

Results: Thirty-one patients with TSF received 123 pemetrexed doses (median, 4 cycles per patient; range, 1-11; mean dose intensity, 97.5%). Seven grade 3/4 drug-related toxicities, including four hematologic, were reported; there were no treatment-related deaths. There was no correlation between TSF amount and type, number, and sequelae of toxicities. Pemetrexed plasma concentrations were within the range of those in patients without TSF. Pemetrexed clearance and central volume of distribution were not statistically different between patients with and without TSF.

Footnotes

Note: Interim results of this study were disclosed as a poster presentation at the 2008 ASCO Annual Meeting, May 31 to June 3, 2008, Chicago, Illinois, and some of the final results of this study were disclosed as a poster presentation at ECCO 15—34th ESMO Congress, September 20-24, 2009, Berlin, Germany.